Gripper cylinder for printing presses



Dec. 26, 1939. B. F. UPHAM I GRIPPER CYLINDER FOR PRINTING PRESSES.

2 SheetsSheet 1 Original Filed March 11, 1938 Dec. 26, 1939. B. F. UPHAM GRIPPER CYLINDER FOR PRINTING PRESSES Original Filed March 11, 1938 2 Sheets-Sheet 2 Patented Dec. 26, 1939 UNHTED STATES GRIPPER CYLINDER FOR PRINTIN PRESSES Burt F. Upham, Grimsby, Ontario, Canada Original application March 11, 1938, Serial No. 195,378. Divided and this application July 21, 1938, Serial No. 220,533

8 Claims.

My invention relates to'printing presses, the present application being a division of my application Serial No. 195,378, filed March 11, 1938.

The present invention provides a novel gripper actuating means for cylinders of printing presses or other mechanisms. Its principal object is to reduce the diameter of the cylinders as compared with the cylinders in presses now used to print sheets of same maximum size; and thus enable rotary sheet printing presses to be operated at higher speeds. Other minor objects of the invention will be hereinafter set forth.

The accompanying drawings illustrate one practical embodiment and utilization of my invention, which I will describe in detail to enable others to understand and use the same. In the claims are summarized the essentials of the invention and the novel features of construction and novel combinations of parts for which protection is desired.

In said drawings:

Fig. 1 is a side elevation partly in section of a portion of a rotary cylinder printing press equipped with a feed cylinder embodying my invention.

Fig. 2 is a top plan view of part of Fig. 1.

Fig. 3 is an enlarged detail view showing the feed cylinder grippers just closed upon a sheet on the feed board.

Fig. 4 is a similar detail view partly in section showing the devices for actuating the feed cylinder grippers to release the sheet.

A number of factors determine the efficient speed at which a printing press or other sheet fed machine may be operated, and there is always a maximum speed beyond which efficiency decreases. The circumference of the printing cylinders (or their equivalents) is a factor affecting this maximum. If the circumference can be reduced, the press (or its equivalent) becomes more efficient.

In the present types of presses using the conventional method of feeding sheets, a cylinder approximately 8 in diameter is required to print a sheet 14 lengthwise of the press. Such a press, operating at 15,000 impressions per hour would have a surface speed of 37,699 feet per hour. By my invention (as described in my aforesaid application) cylinders only 6" in diameter can be employed to print a sheet approximately 14" lengthwise of the press. Such small cylinders are 18.8496" in circumference and except for the approximate 4.8496 required by the gripper gap I can utilize the total available cylinder surface for printing. Assuming the efficient maximum speed of the 6" press to be 15,000 impressions per hour, its cylinders would have a surface speed of 23,562 feet per hour. Thus (if we take the surface speed ofthe 6" cylinder press as standard) the 8" press would produce only 11,250 impressions per hour but the small cylinder press of my invention would be approximately more productive. By the novel method of operation set forth in said application, and in companion divisional application filed July 21, 1938, Serial No. 220,532, the interval between the presentation of one sheet and the next to the sheet stops is shortened, which makes it possible to decrease the circumference of the feeding and printing cylinders.

Referring to Fig. l the sheets are preferably successively taken from a pile as described in my application Serial No. 195,378, and delivered to a conveyor 4. The sheets are successively advanced by the conveyor to sheet registering stops or gages 5, which are normally positioned to ar-- rest the leading edge of the sheet in position to be seized by the grippers 6a of a feed cylinder 6 which delivers the sheet to the grippers la of the impression cylinder 1, coacting with form cylinder 8 to print the sheet.

When the leading edge of a sheet a contacts with the sheet stops 5, the sheet is seized by the grippers 6a of the feed cylinder'G (Fig. 3) and the stops 5 are moved out of the path of the sheet a, which is advanced and transferred to the impression cylinder 1 (Figs. 1 and 4). After sheet a is seized by grippers 6a the stops 5 are returned to stop position before sheet a has entirely passed the stops, and the leading edge of the'following sheet 17 is advanced under sheet a.

In the conventional method of feeding presses, when the leading edge of a sheet contacts with the stops the latter are moved from the path of the sheet and before the stops return to position the entire sheet must pass the stops, and the stops are not returned to operative position until after the tail edge of the sheet has passed. In my method, as set forth in said application, the stops 5 are returned to operative position before the sheet has passed them, and the major part of the time required for the movement of the sheet a past the stops is utilized in positioning the next succeeding sheet I).

In the press shown in Fig. 1 the sheets are ad vanced approximately 2.875 with each cyclic movement of the press. If the smallest sheet is 3", lengthwise of the press, these sheets would have an overlap of The cylinders 6, l, 8 are rotated at uniform peripheral speed, and in the construction shown in Fig. 1 cylinder 1 has a gear 12 on one end meshing with a similar gear 62 on feed cylinder 6, and a gear Hz meshing with a similar gear I82 on cylinder 8.

The upper ends of the stops or gages 5 are bent rearwardly and upwardly as at 5a. The stops 5 may be operated by any suitable means. In the construction shown they are fast to a rock shaft 52) on which is a bell crank lever 515 having one arm pivotally connected to a rod Bu which passes through a rocking eye 5w pivoted on an adjacent part of the frame, and a spring 511 on the rod normally holds rock shaft 5?) and stops 5 in sheet arresting position (Fig. 1). The other arm of lever 52? has a pin 50 engaged with a slot Ed in the upper end of a rod 5e whose lower end is pivoted to the free end of a lever 51 pivoted on a stud 59 on the frame. Lever 51 carries a pin or roller 5h which engages a cam 5i on a shaft 59', and lever 51 is pressed upwardly, to hold roller 5h in contact with cam 52', by means of a spring 5m strung on a rod 570 whose upper end engages lever B and its lower end is slidably engaged with a rocking eye 5;) having a stud 5s pivoted on an adjacent part of the frame. Cam 52' is rotated in unison with the feed cylinder by means of a gear 52 on the cam shaft meshing with a gear I52 on a shaft I511, and gear 152 meshes with gear 72 on cylinder 7 (see Fig. 1)

Because of the small diameters of the impression cylinder and feed cylinder it is impractical to employ the ordinary gripper operating mechanism, and the novel gripper mechanism forming the subject-matter of this application is employed. The gripper mechanism used on the feed cylinder and impression cylinder may be alike, a description of that employed on the feed cylinder will sufiice to explain both.

In Fig. 3 the feed cylinder 6 is shown in end elevation and in position to enable its grippers 6a to take a sheet from the feed table or sheet conveyor. The grippers 6a are mounted on a shaft 6b journaled in the ends of cylinder 6. A tumbler [ii is attached to the gripper shaft at the operators side of the press (Fig. 3), and the grippers are closed by the engagement of tumbler 62' with a pin 6k mounted on the adjacent side frame (see Fig. 2).

On the gripper shaft Eb (Figs. 1, 2 and. 3) is fixed a pinion 6c meshing with a pinion Ed on a stub shaft fie mounted on the adjacent end portion of the cylinder 5. On pinion Ed is a crank pin 6 engaged by the head of a rod 69, the other end of which is guided in an opening in a plate Err attached to the cylinder. A spring 6h interposed between the plate and head of rod 39 normally tends to cause the pinions to rock and hold grippers 5a in closed or open position according to which side of shaft 66 the pin 6 lies after the shaft has been turned by a tumbler pin. This closing occurs when tumbler 62' is tripped by pin 67c.

Adjacent the other end of the cylinder 8 (Figs. 2 and 4) a pinion 6m is fixed on shaft 61) and meshes with a pinion im on a stub shaft 60 mounted on the end wall to of the cylinder. On the inner end of shaft 60 is a short arm 6w to which is pivoted the head of a rod 6r the other end of which passes through a guide plate 61 on the cylinder. A spring 65 strung between the head of rod 61' and plate 6x normally tends to rock pinions 6n, 6m and hold the grippers 6a in open position. The shaft 6b however is held in gripper closing position (after it is closed by action of tumbler 6i and pin 67c above described) until a tumbler St on the shaft 60 of pinion 6m engages a pin Eu on the adjacent side frame (Fig. 2). The pins 6k and Eu are so positioned as to respectively operate the related tumblers at the proper times to cause the opening and the closing of the gripper fingers during each revolution of the feed cylinder.

Because of the small diameter of the feed cylinder and the consequent shortness of the gripper shaft compression springs, I use two springs and cooperating devices mentioned above; which provide simple and novel means for operating the grippers of a cylinder of small diameter such as herein described.

In the press shown, both tumbler pins 6k and Bu are located close to the path of the periphery of a 6 circle, and are respectively engaged by tumblers 6i and (it to respectively close and open the grippers. The conventional tumbler has two channels lineally opposed, and the pin that actuates the conventional tumbler when the grippers are closing is located as in my press, but the pin that opens the grippers with the conventional tumbler is located slightly nearer the center of the cylinder.

If it was attempted to use the conventional tumbler and pins with my small cylinders the closin pin would have to be so located near the center of the cylinder that the arc of movement of the closing tumbler would not be suflicient to move the tumbler into position to be entered by its opening pin. And therefore when the conventional tumbler is used the diameter of the cylinder cannot be reduced below a certain minimum.

In Fig. 4 the feed cylinder is shown in the position it would take shortly after a sheet has been transferred to the impression cylinder 1 (Fig. 1).

I have not shown in detail the operating mechanism of the impression cylinder grippers, as it could be a substantial duplicate of that used in the feed cylinder, as above described, the tumbler actuating pins being properly located to cause the closing and opening of the impression cylinder grippers at the proper points in its revolution.

In order to enable the following portion of a sheet (a) taken by the feed cylinder to be raised by the stops 5 to facilitate the advancing of the next succeeding sheet thereunder, the periphery of the feed cylinder may be partially further reduced in diameter, as indicated at 660, as by recessing its periphery, the outer extremity of the part 86 (Figs. 3 and 4) showing the full diameter of cylinder 6, which corresponds to the full diameter of impression cylinder 1.

I claim:

1. An impression cylinder of minimum diameter for printing presses having all its surface available for printing except the gripper gap; a gripper shaft mounted in the gap; and a pair of tumblers on said shaft adapted to be engaged by fixed pins disposed adjacent the periphery of the cylinder to open and close the grippers during 7 each revolution of the cylinder.

2. A feed cylinder for printing presses having a gap and having its periphery reduced to permit the following portion of a sheet taken thereby to be lifted to facilitate feeding of the next succeeding sheet thereunder; a gripper shaft mounted in the gap; and a pair of tumblers on said shaft adapted to be engaged by fixed pins disposed adjacent the periphery of the cylinderto Ill open and close the grippers during each revolution of the cylinder.

3. A feed cylinder of small diameter having a set of gripper devices and having its periphery reduced to permit the following portion of a sheet taken thereby to be lifted to facilitate feeding and positioning of the next succeeding sheet thereunder; and a pair of tumblers on said cylinder for operating said gripper devices adapted to be engaged by fixed pins respectively disposed adjacent the periphery of the cylinder to open and close the grippers during each revolution of the cylinder.

4. In a printing press, a gripper feed cylinder of small diameter having a set of gripper devices and having its periphery reduced to permit the following portion of a sheet taken thereby to be lifted to facilitate feeding the next succeeding sheet, and a pair of tumblers on said cylinder for operating said gripper devices adapted to be engaged by fixed pins respectively disposed adjacent the periphery of the cylinder to open and close the grippers during each revolution of the cylinder, and sheet stops adapted to be returned to sheet arresting position before the sheet taken by the feed cylinder has fully passed the stops.

5. In combination, a cylinder, a gripper shaft mounted therein, a tumbler at one end of the cylinder for rocking said shaft to close the grippers, a fixed pinadjacent the periphery of the cylinder for engaging said tumbler adjacent that end of cylinder; a second tumbler at the other end of the cylinder for rocking said shaft to open the grippers, and a second fixed pin adjacent the periphery of the cylinder for engaging the second tumbler adjacent that end of cylinder;

6. In combination, a cylinder, a gripper shaft mounted therein, a tumbler at one end of the cylinder for rocking said shaft toclose the grippers, a fixed pin adjacent the periphery of the cylinder for engaging said tumbler adjacent that end of cylinder; a, second tumbler at the other end of the cylinder for rocking said shaft to open the grippers, a second fixed pin adjacent the periphe'ry of the cylinder for engaging the second tumbler adjacent that end of cylinder, and spring means at each end of the cylinder for throwing the shaft when either tumbler is actuated by its related pin.

7. In combination, a cylinder, a gripper shaft mounted therein, a tumbler at one end of the cylinder for rocking said shaft to close the grippers, a fixed pin adjacent the periphery of the cylinder for engaging said tumbler adjacent that end of cylinder; a second tumbler at the other end of the cylinder for rocking said shaft to open the grippers, and a second fixed pin adjacent the periphery of the cylinder for engaging the second tumbler adjacent that end of cylinder, said cylinder having a peripheral pocket to permit the following end of the sheet carried thereby to be lifted to'permit the succeeding sheet to be fed thereunder.

8. In combination, a cylinder, a gripper shaft mounted therein, a tumbler at one end of the cylinder for rocking said shaft to close the grippers, a pin for engaging said tumbler adjacent that end of cylinder; a second tumbler at the other end of the cylinder for rocking said shaft to open the grippers, a pin for engaging the second tumbler adjacent that end of cylinder, a pinion on the shaft adjacent each end thereof, a second pinion mounted on the adjacent end of the cylinder and engaging the adjacent pinion on the rock shaft, and spring means for rocking the pinions.

BURT F. UPI-1AM. 

